Friction-clutch.



J1 c. BRBWIN FRICTION CLUTCH. APPLICATION I'ILED DEG.14, 1910.

1,008,945, Patented Nov. '14, 1911.

2 SHEBTBSHEET 2.

MINI H Mine was: 5 vwaWbo z:

' JDHN C, B/fEW/N W. 1

{l $513M 6111011411 0 I COLUMBIA PLANOGRAPH 120.. WASHINGTON, D- C.

JOHN G. BREWIN, 0F PHILADELPHIA, PENNSYLVANIA.

FRICTION-CLUTCH.

Specification of Letters Patent.

Patented Nov. 14, 1911.

Application filed December 14, 1910. Serial No. 597,383.

To all whom it may concern:

Be it known that I, JOHN C. BREWIN, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inFriction-Clutches, of which the following is a specification, referencebeing had therein to the accompanying drawing.

This invention relates to that type of friction clutches in which theconnection between the driving and driven elements is effected by anexpansion member carried by one of the parts and adapted to be expandedto frictionally engage the other element.

The invention is especially applicable to clutches of this type in whichthe driving element is in the form of a constantly rotating pulley orequivalent device, and in which the driven element is in the form of ashaft normally at rest, the expansion member, usually in the form of aring, being sustained by the shaft and adapted by its expansion toengage the inner surface of the pulley; whereby the motion of the pulleywill be transmitted to the shaft. It is manifest, however, that thisarrangement of the parts may be reversed, that is, the shaft may be thedriving element and the pulley the driven element.

The invention consists of various improvements in clutches of thischaracter designed to render the action of the expansion ring speedy andcertain in its engagement with the pulley; to provide for the convenientand effective adjustment of the expansion ring to take up wear betweenthe same and the pulley; to render the arrangement and construction ofthe parts compact and simple; and generally to improve the action andoperation of the mechanism as a whole.

In the accompanying drawings: Figure 1 is a face view of my improvedmechanism with certain parts in section. Fig. 2 is a longitudinalsection on the line a-a of Fig. 1. Fig. 3 is a side elevation, partly insection, showing the lever mechanism for controlling the action of theclutch.

Referring to the drawings: 1 indicates the driven element-in the presentinstance in the form of a shaft normally at rest and mounted forrotation in bearings 2 in a suitable frame 3. Loosely mounted on theshaft is a driving element 4-in the present instance in the form of apulley adapted to be rotated constantly from any suitable source ofpower.

5 indicates a clutch disk provided with a hub 5 encircling the shaft andsecured firmly thereto, preferably by means of a setscrew 5 extendingthrough the hub and engaging the shaft. The outer peripheral edge of thedisk terminates within the peripheral flange of the pulley, and isformed in. its side face, near its edge, with a circumferential recess6, in which is seated an expansion ring 7 fitting normally looselywithin the peripheral flange of the pulley, and adapted when expanded toimpinge and bind against the inner surface of said flange, by whichaction a driving connection is effected between thepulley and shaft.

The expansion ring extends continuously for nearly the entirecircumference of the pulley flange, a short space being left between thedisconnected ends of the ring, as indicated at 8. Pivoted to the side ofthe clutch disk on an axis 9 parallel with the shafts axis, is anexpansion lever 10, the outer end of which is adapted to engage one endof the expansion ring, while its inner end terminates adjacent thecenter of the disk in position to be engaged by a clutch lever 11. Theclutch lever extends longiiudinally of the shaft and is pivoted on atransverse axis 11 between ears 11 extending outwardly from the diskhub, one end of the lever 11 being extended over the inner end of theexpansion lever in position to engage it, while the opposite end of theclutch lever is extended at the side of the shaft beyond the disks hub,so that this end of the clutch lever may be acted on by meanshereinafter described to move the same outwardly and correspondinglymove its opposite end inwardly. By this action, the expansion lever willbe rocked on its axis and its outer end caused to move the end of theexpansion ring in a circumferential direction to effect the expansion ofthe same.

The opposite end of the expansion ring is engaged by the outer end of alever 12 pivoted between its ends on an axis l2 parallel with the shaftsaxis and carrying at its inner end a radially extending pin 13, theouter end of which engages the inner surface of the expansion ring somedistance from its end. This lever, by its engagement with the end of theexpansion ring, will be rocked on its axis by the circumferentialmovement of the ring due to the action of the expansion lever on theopposite end, and such rocking action of lever 12 will ,force the radialpin 13 outwardly against the inner side of the ring. This will cause thering at this point to be moved outwardly and bind against the innersurface of the pulley, while at the same time checking furthercircumferential movement of the ring against the lever 12, so that thecontinued movement of the expansion lever will expand the ringthroughout its extent and cause the same to bind evenly and firmlyagainst the inner surface of the pulley.

It will be observed that by reason of the provision of the radiallyacting pin 13, the expansion ring, in addition to the expansive actioncaused by the separation of its ends, is subjected to a distinctexpansive force acting directly thereon between the ends of the ring andoperating to urge the same outwardly in a radial direction, whereby thequick and sure contact of the ring is assured. This I deem an importantfeature of my invention, and it is manifest that the detailed mechanismfor accomplishing the same may be variously modified within theknowledge of the skilled mechanic without departing from the limits ofthe invention, the essential feature of the invention in this connectionbeing means, broadly, for subjecting the ringto an outward pressure at apoint between its ends, in addition to its expansive movement due to theseparation of its ends.

The radial pin 13 is connected with the lever 12 in such manner that itmay be adjusted relatively thereto to and from the ring. This isconveniently effected by threading the inner end of the pin into thelever. The purpose of this arrangement is to take up wear that mightoccur between the outer surface of the ring and inner surface of thepulley, the movement of the pin outwardly relative to the lever causingsuch a change in the relation of the ring to the other mechanism thatany lost motion between them, due to wear, will be taken up and theirproper operative relation maintained.

It will be noted that the ring is entirely disconnected at its ends fromthe operating mechanism. As a result of this fact, the ring will give amore uniform contact with the pulley, as it is free to move outwardlyuniformly at every part in relation to the operating mechanism, and isnot restrained by any permanent connection with the operative parts, ashas heretofore been the case.

As a result of the form and relation of the two levers 10 and 12, andtheir action on the ends of the expansion ring, a leverage of about 4 :1on the ring is produced, without requiring any extension of the shaft atthe pulley side of the clutch beyond that suitable for giving the shafta bearing at this point. Consequently, the mechanism may be included insmall limits and arranged in compact form.

The end of the clutch lever may be moved outwardly in any suitablemanner to actuate the ring-expanding mechanism, but I prefer to adoptfor this purpose an actuating conemember 14 mounted to slide back andforth on the shaft 1 adjacent the end of the clutch lever, the said conemember being formed with an inclined or sloping circumferential surface14: adapted to engage the end of the lever. Normally and when the clutchis disengaged, the lowest part of the sloping surface will be inengagement with the end of the lever, so that the lever will extend in ahorizontal position, as shown in Fig. 2. When, however, the cone memberis moved along the shaft and in the direction of the arrow of Fig. 3,the sloping surface will engage with the lever and move its endoutwardly, thereby depressing the opposite end of the lever andactuating the expansion lever as hereinbefore described. Any appropriatemeans may be employed for shifting the cone member on the shaft to thuscontrol the clutch, one convenient form of mechanism being shown, andconsisting of a hand lever 15 pivoted to the frame of the machine andhaving a pin 15 engaging in a circumferential groove in the cone member,the movement of the hand lever back and forth causing the cone member tobe correspondingly shifted;

In the accompanying drawings I have illustrated my invention in theparticular form which I prefer to adopt and which has been found inpractice to answer to a satisfactory degree the ends to be attained, butit will be understood that my invention is not limited to any particularform or construction of the parts except in so far as such limitationsare specified in the claims.

Having thus described my invention, what I claim is 1. In a frictionclutch, and in combination with a driving element, a driven element, anexpansion member sustained by one of said elements, means for moving oneend of said member circumferentially, and a movable device engaged bythe other end of said member, said movable device also engaging theexpansion member between its ends to apply outward pressure thereto.

2. In a friction clutch, and in combination with a driving element, adriven element, an expansion member sustained by one of said elementsand adapted to engage the other, means for moving one end of the membercircumferentially, a movable device engaged by the other end of theexpansion member, a pressure pin carried and operated by said movabledevice and engaging the expansion member, and means for adjusting thepin relatively to the movable device.

3. In a friction clutch, and in combination with a driving element, anda driven element, one of said elements being in the fo rm of a shaft andthe other in the form of a pulley, a clutch disk fixed to the shaft, anexpansion ring adapted to engage the inner surface of the pulley, anexpansion lever pivoted to the disk and engaging one end of the ring,means for actuating said lever, and a movable device carried by the diskand acted on by the other end of the ring and operating to applypositive outward pressure to the ring.

t. In a friction clutch, and in combination with a driving element, anda driven element, one of said elements being in the form of a shaft andthe other in the form of a pulley, a clutch disk fixed to the shaft, anto engage the inner surface of the pulley, an expansion lever pivoted tothe disk and engaging one end of the ring, means for actuating saidlever, a second lever pivoted to the clutch disk and engaged by theother end of the ring, said second lever belng formed and arranged toapply pressure to the ring between its ends. In testimony whereof I haveafiixed my signature in presence of two witnesses.

JOHN G. BREWIN.

Witnesses:

EDWARD TREDIoK, JOSEPH B. GoDsHALL.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

